In the following tests, we examined the DVD reading capabilities of the drive with
scratched / defective DVD media. For the tests, we used CDVD Benchmark
and Nero CDSpeed. The reference test media comes from ALMEDIO.

- Single Layer media

ABEX TDR-821

This is a single sided, single layer DVD-ROM with a 4.7GB capacity, and its surface has an artificial scratch of dimensions varying from 0.4 to 3.0 mm.

ABEX TDR-825

This is also a single sided, single layer DVD-ROM of 4.7GB
capacity. The data structure of the disc is exactly the same as that of the
TDR-821, with the difference that there are no scratches on it but instead,
defective areas of dimensions ranging from 0.5 to 1.1 mm.

There are also fingerprints sized between 65 and 75 micrometers.

- Dual Layer media

ABEX TDR-841

This is an 8.5GB dual layer, single sided DVD-ROM disc with artificial scratches of dimensions ranging from 0.4 to 3.0mm, on both layers.

ABEX TDR-845

The disc is a single sided, dual layer DVD-ROM disc with a capacity of 8.5GB.
The only difference between the TDR-845 and the TDR-841 is that the first includes
defective areas and fingerprints.

The dimensions of the defective areas range from 0.5 to 1.1 mm and the fingerprints
are sized from 65 to 75 micrometers.

ABEX TDV-541

The TDV-541 is a single sided, dual layer DVD-VIDEO disc, with a capacity
of 8.5GB.The disc is based upon the TDV-540 series which is designed for inspection
and adjustment of DVD-VIDEO players. The disc checks the layer switch operation
from layer 0 to layer 1 and also includes test pictures and test signals for
DVD sound files.

The current TDV-541 also checks the error correcting capabilities of
the drive and includes scratches from 0.4 to 3.0 mm.

There were no errors but the drive dropped speed down to 2X just after the layer switch.

ABEX TDV-545

The TDV-545 disc is based on the TDV-540 series. It is a single sided, dual layer DVD-VIDEO disc with a capacity of 8.5GB.

The TDV-545 includes artificial black dots on the data surface, sized from
0.4 to 1.0 mm. It also has 65 - 75 micrometer fingerprints.

- Summary

Overall, excellent error correction mechanism with DVD media. There were no errors with any of the media, although there was a sharp drop in speed with the TDV-541.